Ferrite Inductor Calculator - Calculator Academy

Choose inductance, turns, or A_L value, then enter the two required quantities. Results include unit conversions and calculation details.

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Ferrite Inductor Formula

The following equation is used to calculate the ferrite inductor inductance from the core’s inductance factor (A_L) and the number of turns.

L = A L \times N²

Where L is the inductance (H)
A_L is the inductance factor of the ferrite core (H/turn², often specified as nH/turn² by manufacturers)
N is the number of turns on the ferrite core

To calculate the inductance of a ferrite inductor, multiply A_L by the square of the number of turns. Use the manufacturer’s A_L value under the intended measurement conditions; saturation, frequency, temperature, tolerance and winding effects can change actual inductance.

What is a Ferrite Inductor?

Definition:

Ferrite inductors are a type of inductor known for strong electromagnetic properties. These inductors have a ferrite core that provides them with low electrical conductivity (high resistivity) compared to metallic cores, which helps reduce eddy-current losses.

How to Calculate Inductance of Ferrite Inductor?

Example Problem:

The following example outlines the steps and information needed to calculate the inductance of a ferrite inductor.

First, determine the A_L value (inductance factor). This value is typically provided by the core manufacturer (often in nH/turn²). For this problem, assume A_L = 50 nH/turn².

Next, determine the number of turns of the inductor. In this example, the number of turns is 30.

Finally, calculate the ferrite inductor inductance using the formula above:

L = A_L × N²

L = 50 nH/turn² × (30)²

L = 50 × 900 nH = 45,000 nH = 45 μH